Properties of Asphalt Concrete

Asphalt Concrete

Asphalt concrete is a mineral bituminous construction material produced by compacting of asphalt concrete mix. The latter usually consists of gravel, sand, mineral powder and oil bitumen heated to 120-160ºС and mixed in the proper ratios.

The percentage of components of asphalt concrete mix:

  • 20-65% gravel;
  • 30-66% sand;
  • 4-14% mineral powder;
  • 5-7% bitumen.

Asphalt concrete differs from other bituminous-mineral materials, with higher density, strength and water resistance. These properties are achieved by the application of a special mineral powder and precise portioning of all components.

One of the important advantages of asphalt concrete is its ability to be used in construction of automobile roads of almost any category, including roads with the highest traffic intensity and severe transport loads.

Comparing asphalt concrete with cement concrete, we can note that the former is characterized by thermoplasticity, that is, softening on hot days and hardening on cold days. This is caused by the binder of asphalt concrete, i.e. bitumen.

The structure of a road includes several layers: base, top and bottom layers.

The base has several layers as well. The upper layer is built with coherent materials, while the lower one is built with discrete materials. Highly porous asphalt concrete is a coherent material. Gravel and mineral mixes made of rock or industrial waste are discrete materials.

The top layer consists of one or two layers of asphalt concrete: the upper part us built with compacted fine material, the lower part contains coarse material, porous, hot or warm.

With correct construction of road structure and proper shear resistivity, fracture strength, water and frost resistance, asphalt concrete coating can serve for more than 20 years without deformations or structural failure.